This invention regards made from vibrated or pre-stressed reinforced concrete and, in particular, refers to a prefabricated girder in two halves to the means for joining the two halves together statically at the moment of using the girder, as well as a roof structure made from such girders, for buildings with a circular, polygonal or elliptical plan, both for civil and industrial use.
According to the techniques available, pre-fabricated girders in reinforced concrete, including those with a flat, T-shaped or H-shaped intrados, have, so far, been made in a single piece, using an unbroken metal reinforcement, even when consisting of remarkable length. However, when they are particularly long, their construction requires moulds which are extremely cumbersome and difficult. Furthermore, transporting such girders becomes awkward as a result of their size and weight. Road transportation can also be problematic where the roads are narrow or in the mountains, especially when special transport vehicles are called for.
One aim of this invention is to propose a girder, in particular with a flat intrados, consisting of two symmetrical halves and where the two halves are connected by a joint device which ensures similar resistance and static characteristics to those girders made in a single piece.
Another aim of the invention is to create a girder with a flat intrados and a flat or sloping extrados, which will have the advantage of using less cumbersome moulds for its construction, for simpler casting, easier manoeuvrability and transportation, even in difficult circumstances and with girders of notable length, giving girders of a length which have been very uncommon to date and, finally, reducing production and transportation costs of said girders.
A further aim of the invention is to create reinforced concrete girders, with a T-shape or H-shape, in two symmetrical halves that can be joined together at the moment when the girder is employed at its final site, where there will also be the advantages of facilitating manoeuvring and transportation, without having recourse to special vehicles.
Yet another aim of the invention is to propose a roof structure with a circular, polygonal elliptical or similar plan, consisting of half-girders which are pre-fabricated in reinforced concrete, easily transportable, converging and connected in a simple and secure way at the moment of erecting, by the simple process of screwing together the joint devices.
Consequently, the invention proposes a girder in vibrated or pre-stressed reinforced concrete, consisting of two opposing symmetrical halves, where the adjacent parts match together in a plane which is perpendicular to the intrados of the girder, and which are equipped, near to the extrados, with plates that connect using bolts and, near to the intrados, with a joint device with rods.
Likewise, the invention proposes a roof structure for buildings with a circular, polygonal, elliptical or similar structure, consisting of numerous half-girders, each with a near end and a far end (12), incorporating longitudinal connecting rods, each of which have a threaded end that protrudes from the near end, and of means for connecting the near ends of the half-girders at the level of the threaded ends of the connecting rods, using safety nuts, while the far ends of the half-girders rest on pillars or other supports.